Grab friendly monsters and destroy the evil ones in Monstars' adorable yet hardcore action game, Kotomon. We also have an app that allows you to put on your own fireworks display, and an interactive children's coloring book.

All app prices are subject to change at any time and without notice regardless of stated free duration. Price changes are solely under the control of the developers.

iPhone:

Real Fireworks Artwork Visualizer ($2.99 → Free, 4.2 MB): Put on your own fireworks show safely indoors with this entertainment app. Tap all over the screen to set off colorful explosions, or change a variety of parameters and allow the app to perform the show all on its own. You're also able to choose from seven different modes, including one that allows you to draw your own images. The app includes multitouch controls, five color options, the ability to capture and share your works of art, and TV-out support.

Real Fireworks Artwork Visualizer is available for free for a limited time. It has a 5-star rating with a total of 17 ratings.

Demolition Master: Project Implode All ($0.99 → Free, 27.1 MB): Become a demolition master by flattening structures using a limited amount of explosives in this physics-based puzzle game. Attach explosives to the structures by dragging and dropping them into place. Then just sit back and watch as they come tumbling down. The game includes 16 locations, 240 levels, and leaderboards via Game Center.

Demolition Master: Project Implode All is available for free for a limited time. It has a 4-star rating with a total of 700 ratings.

SLIDING HEROES ($0.99 → Free, 39.9 MB): Square Enix’s real-time strategy game where you slide your units across the map by tilting your iDevice in order to conquer the over 130 levels. The game includes two modes, 30 maps, three environments, four unit classes, and much more.

SLIDING HEROES is available for free for a limited time. It has a 3-star rating with a total of 800 ratings.

Universal:

Princess Fairy Tale Coloring Wonderland for Kids and Family Preschool Ultimate Edition ($1.99 → Free, 24.2 MB): Help the princess fill the world with color in this interactive children's coloring book. Your child can fill in 11 different scenes just by tapping on the colorless canvases. As your child works their way through each scene, new interactive characters and items will appear. The app also includes helpful hints, so even young children can join in on the fun.

Princess Fairy Tale Coloring Wonderland for Kids and Family Preschool Ultimate Edition is available for free for a limited time. It has a 5-star rating with a total of 10 ratings.

Ice Age Movie Storybook Collection ($0.99 → Free, 47.1 MB): Tag along with Manny, Sid, Diego, and the rest of the crew from Ice Age as they go on their first big adventure in this storybook based on the hit film. You're able to read through the entire book all yourself, or you can follow along with the narrator. The app includes vivid images from the original motion picture, genuine character audio narration, and the ability to jump to a specific page. Additional books are available via in-app purchase.

Ice Age Movie Storybook Collection is available for free for a limited time. It has a 3.5-star rating with a total of 16 ratings.

Death Rider ($0.99 → Free, 32.7 MB): Speed ahead in your machine gun-equipped Death Rider for as long as possible in this arcade game. You're able to steer your vehicle via tilt or touch, and you can fire your weapons via on-screen buttons. Take out your opponents by blasting them to bits or ramming them off of the road to earn points. Grab coins along the way to unlock new vehicles, maps, and upgrades. The game includes 10 vehicles, and leaderboards via Game Center.

Death Rider is available for free for a limited time. It has a 4.5-star rating with a total of 10 ratings.

KOTOMON ($3.99 → Free, 42.1 MB): Help Kotomon wipe out the enemy monsters in this adorable yet hardcore action game. You're able to guide Kotomon around the environments by sliding your finger over the lower half of the screen. Grab friendly monsters by walking into them, and fire them at your enemies by tapping the screen. Friendly monsters vary in size, shape, color, and ability, so hunt down as many different kinds as you can. Every move you make adds to the beat of the background music as well, allowing you to influence the soundtrack. The game includes 25 friendly monsters, eight environments, and 24 levels.

KOTOMON is available for free for a limited time. It has a 4-star rating with a total of 42 ratings.

Real Fireworks Artwork 4-in-1 HD 2012 - Play Awesome Light Show, Enjoy Fun Visualizer, Make Cool Wallpapers and Draw Amazing Art with Colors & Glow is available for free today only (12/28). It has a 4.5-star rating with a total of 405 ratings.

Demolition Master HD: Project Implode All ($0.99 → Free, 32.2 MB): Become a demolition master by flattening structures using a limited amount of explosives in this physics-based puzzle game. Attach explosives to the structures just by dragging and dropping them into place, and then just watch as they come tumbling down. The game includes 16 locations, 240 levels, and leaderboards via Game Center.

Demolition Master HD: Project Implode All is available for free for a limited time. It has a 4-star rating with a total of 949 ratings.

Verde ($4.99 → Free, 2.5 MB): This utility app allows you to find out how much money and carbon can be saved by upgrading the old appliances in your home. It takes into account your climate zone and electricity rate, and then requires you to go through a variety of categories to register all of your electronic devices. The app then gives you a final report on your potential cost and carbon savings, and allows you to share it via Twitter or Facebook.

Verde is available for free for a limited time. It has a 4-star rating with a total of 24 ratings.

That concludes today's issue of Apps Gone Free. If you like staying on top of these daily deals, don't forget to check out our free AppsGoneFree app. It provides all the deals each day, and even an archive of past deals that are still active.

Developers:

If you are a developer who would like to get your app included in our “Apps Gone Free” daily lists, here’s our basic set of rules:

It must have at least a three-star average rating at the time it goes free.

The app must not have been free numerous times (3+) over the last six months.

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To submit an app, simply send a request to [email protected] with the subject “Apps Gone Free.” Please include the name of the app, a link to it in the App Store, when and for how long you intend to offer the app for free, and anything else you would like to share. We will take it from there.